The invention relates generally to power electronics and, more particularly, to advanced cooling for power electronics.
High power converters, such as medium voltage industrial drives, frequency converters for oil and gas, traction drives, Flexible AC Transmission (FACT) devices, and other high power conversion equipment, for example rectifiers and inverters, typically include press-pack power devices with liquid cooling. Non-limiting examples of power devices include integrated gate commutated thyristors (IGCTs), diodes, insulated gate bipolar transistors (IGBTs), thyristors and gate turn-off thyristors (GTOs). Press-pack devices are particularly advantageous in high power applications, and benefits of press-packs include double-sided cooling, as well as the absence of a plasma explosion event during failure.
To construct a high power converter circuit using press-pack devices, heat sinks and press-pack devices are typically sandwiched to form a stack. State-of-the-art power converter stacks typically employ conventional liquid cooled heat sinks with larger diameter cooling channels. In certain applications, thermal grease layers are disposed between respective ones of the press-pack device and the conventional liquid cooled heat sink. In other applications, at least some of the layers are simply held together by pressure, with no thermal grease in between them. This arrangement results in significant thermal contact resistance.
It would be desirable to provide improved heat sink designs which prevent the coolant from leaking onto the electronics during assembly, disassembly, or servicing. It would further be desirable to provide improved heat sink designs that enable the use of heat spreading effects for enhanced cooling of power electronics. In addition, improved heat sink designs with lower manufacturing costs and enhanced heat transfer are also desired.